Bilge water is water which enters a ship by any means and lies upon her inner bottom or bilge. It is desirable to remove the bilge water from the vessel and several systems have been devised which attampt to accomplish this goal. However, most currently used methods of bilge discharge are deficient in their effectiveness. Two types of bilge draining systems include pump and pumpless bilge draining systems. While pumpless bilge drainers are known, they restrict themselves in such a way as to be the casual effect for jeopardizing the safety of the vessel.
Specifically, U.S. Pat. No. 831,633 issued to Charles W. Moore teaches a pumpless bilge drainer gate system. However, Moore's device is difficult to utilize in that it does not provide for above load water line control of the drainer. The Moore drainer relies on a check valve 22, to control water reentry into bilge. Should the check valve be offset for any reason, the craft is in jeopardy of taking in water thus resulting in possible submersion of the vessel. A second type of pumpless bilge drainer is embodied in G. A. Woods' issued U.S. Pat. No. 1,578,621 which discloses a valveless air vent using a pressure induced suction as a means for bilge water removal. However, such a teaching does not take into account the possibility of a failure of clogging of the vent. Should the vent become clogged with debris, a reverse syphonic effect will occur and cause water to enter the vessel, jeopardizing the craft, contrary to the intent of Woods. In addition, Wood does not teach the use of a valve to control water action or to provide a means of regulation.
Electric bilge pumps are well known throughout the industry, however, such pumps have a high system failure rate primarily due to poor electrical bilge wiring, stuck float switches, debris in the pump intake and water intrusion into the submerged pump or float switch. Additionally, maintenance is a significant problem with an electric bilge pump system. Moreover, in a pump of the centrifical type, once the water level is below the intake at the bottom of the pump and/or the float switch cuts off, remaining bilge water in the above waterline discharge hose flows back into the vessel.